Grinding machines for grinding camshafts and crankshafts are known in the art. For rough grinding, such a machine may use a grinding wheel spindle having a steel hub, onto which a single layer of cubic boron nitride (CBN) grains are held by an electroplated layer of material such as nickel to provide a grinding wheel with a grinding surface around the circumference of the wheel.
Over the life of the wheel, the grains are worn down and the nickel layer is eroded. This is a gentle and slowly-evolving condition during the life of the wheel. However, at some point, damage to the bonding layer becomes catastrophic, resulting in grain loss. This then transfers more of the cutting load to the remaining active grains. Rapidly, grains are stripped, causing failure of the grinding surface, and rubbing between the metal wheel hub and workpieces takes place producing extremely high forces on the grinding spindle bearing system. If continued, the additional grinding may overload the grinding motor and/or damage the grinding wheel spindle. In order to avoid spindle damage and motor overload, grinding wheels are prematurely replaced after a set number of grinds. Consequently, grinding wheels which may still be usable are prematurely replaced, resulting in increased manufacturing costs.
A method of determining when a grinding wheel is near the end of its life cycle is desired to prevent excessive grinding machine wear or damage while avoiding premature replacement of usable grinding wheels.